Improvement in governor-valves for steam-emgines



W. A. COGSWELL.

Improvement in Governor-Valves for Steam-Engi nes.

Patented Aug. 13,1872.

UNITED STATES WILLIAM A. G OGSWELL, OF ROCHESTER, NEW YORK, ASSIGN OR TO J UNIUS JUDSON, OF SAME PLACE.

. IMPROVEMENT IN GGVERNORNALVES FOR STEAM-ENGiNES.

Specification forming part of Letters Patent No. 130,480, dated August'l3, 1872.

SPECIFICATION.

To all whom it may concern:

Be it known that 1, WILLIAM A. (loss- WELL, of the city of Rochester, in the county of Monroe and State of New York, have invented a certain new and useful Improvement in Pistons for Governor-Valves, of which the following is a specification:

Nature of the Invention.

General Description.

In the drawing, Figure 1 is a section of a governor valve-casing with my improved piston applied therein. Fig. 2 is a perspective view of the piston.

A represents the body of the piston, which has two heads or bearings, a a, which rest in seats b b of the casing. The upper head is made of a larger diameter than the lower head for a twofold purpose, viz.: First, to enable the lower head to draw easily through the seat of the upper head when the piston is to be withdrawn from the casing; and, second, to produce a slight overbalance of pressure upward against the upper head, so as to keep the piston-rod and governor-arms in firm connection and make the governor more sensitive and regular in its action.

Much difficulty has been experienced heretofore in removing the piston from the casing, as the two bearing-heads have both been made of the same diameter, and rust and sediment gather on the lower one, which prevents a ready passage. By making the upper'head the largest I obviate all difficulty of this kind. A more special advantage consists in producing a slight overbalance of pressure upward against the upper head, which takes up any slack or lost motion in the connecting-rod between the piston and balls; in other words, the upward pressure keeps the rod pressed up against the short ends of the governor-arms in all positions of the balls, and thus prevents any loose play between those parts; also, it counteracts any sudden impulse of the engine to throw the balls too high by following the rod up and holding under the arms, thus preventing any oscillation or vibrating of theballs which affect their sensitiveness, and also cause the piston to cut off too much by a sudden motion downward. My arrangement produces a steady action of the cut-off, which cannot be produced by an equalized pressure upon both heads of the piston. In these respects the enlargement of the upper head has a special relation to the piston of the Graduated Judson Governor-Valve. The lower head a is provided with three legs or projections, d d d, which form bearings in the sea-t when the body of the valve is raised, and thus keep it in place. This head also has three graduated openings, f f f, similar to the graduated openings in J udsons valve-piston, said openings being located equidistant between the legs, as shown clearly in Fig. 2. Heretofore two legs or projections have been used; but, in order to make them effective in centering the piston, they have been made with lateral or side extensions or wings, which cover considerable space in the seat. The objection to such an arrangement is, that the steampassage is greatly obstructed by these extensions, and also much friction occurs. By the use of three legs, as in my improvement, the piston will be kept centered without the side wings or extensions, andthey can be made very small, so as to form but little obstruction to the steam-passage. The use of more than three would be superfluous for the purpose designed-viz., to center the piston-and would form an unnecessary obstruction to the steam-passage. The three graduated openings intermediate with the legs or projections equalize the pressure upon the piston, and prevents side action or any binding of the piston in its seat. The upper head a is also provided with bearings g gg, which stand with J udsons graduated piston, as speciout from the body of the piston and serve to keep the latter in position in its seat.

Claims.

WVhat I claim, and desire to secure by Letters Patent, is

1. The head a, constructed with the three or more bearing-legs, d d d, and three or more graduated openings, f ff, intermediate therewith, as herein described, when combined 2. The head a, constructed as described, in combination with the head a, substantially as and for the purpose set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing ARoHD. BAINE. 

